Welcome to the Darrouzet-Nardi Lab homepage!
I am an assistant professor in the Biological Sciences department at the University of Texas at El Paso. I started at UTEP in January and am setting up a new research lab. The goal of my program is to examine the effects of global change drivers such as climate change on mountain, desert, and Arctic tundra ecosystems using ecological field experiments.
I am now recruiting students, so please contact me if you are interested in joining my lab!
Department of Biological Sciences
500 W. University Ave.
University of Texas at El Paso
El Paso, TX 79968
Climate change in dryland ecosystems
Just before I came to UTEP, I began working on a project designed to explore the response of biological soil crusts to elevated temperature and changing moisture regimes. Our analyses of carbon fluxes in a multiyear 2°C warming experiment (IR lamps) showed clear temperature effects on net soil exchange (NSE) of CO2 both throughout the year and between warming treatments and controls. These results provide experimental evidence for the hypothesis that increased temperature in semiarid ecosystems will drive carbon loss in crust-dominated soils.
Changing seasonality of plant-soil interactions in the Arctic tundra
Arctic soils contain large stocks of carbon and may act as a significant CO2 source in response to climate change. Using an early-snowmelt×warming manipulation at a site near Toolik Field Station on Alaska's North Slope, our team investigated changes in soil nutrient cycling in response to changing climate and seasonality. Our results indicate that snowmelt acceleration causes more rapid early-season nutrient immobilization in soils and that snowmelt acceleration in unwarmed plots can cause season-long reductions in root growth and inorganic N availability due to plant exposure to harsh conditions in the absence of snow.
Landscape heterogeneity of nitrogen cycling in an alpine-subalpine ecosystem (Dissertation)
Microbially mediated nitrogen cycling rates are heterogeneous across landscapes, with disproportionate activity occurring in biogeochemical hot spots. My dissertation examined landscape heterogeneity in soil nitrogen (N) cycling pools and fluxes in a 0.89 km2 site at the alpine-subalpine ecotone. Some of my key findings were: (1) A large percentage of total inorganic N pool sizes and associated cycling rates were attributable to a small percentage of hot spots. (2) A spatially complementary relationship was discovered between atmospheric N deposition and N-fixing plant abundance.
Sagebrush encroachment in subalpine meadows of the Sierra Nevada Mountains
Meadows in the southern Sierra Nevada Mountains have been encroached upon by sagebrush (Artemisia rothrockii) due to groundwater decline associated with livestock grazing. Our team conducted a three-year study on the ecosystem effects of this encroachment. We discovered that sagebrush transpiration does not dry out the soil during encroachment as we hypothesized it might. Using stable oxygen isotopes, we also showed that both young sagebrush plants and resident herbs used shallow soil water but were also able to access deeper water.